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Electrospark deposition (ESD) attracts special attention from scientists and engineers because of its unique advantages. However, the ESD process has been carried out by…
Electrospark deposition (ESD) attracts special attention from scientists and engineers because of its unique advantages. However, the ESD process has been carried out by hand up to the present. This prevents ESD from preparing complex curve/surface coatings owing to manual operation characteristics. To meet the coating precise preparation requirements for a lot of parts with complex surface from various industrial fields, this paper aims to obtain a new automatic ESD equipment, process and preparation methodology for complex surface coatings.
By designing a special deposition holder and re-programming programmable machine controller, an ESD power supply and a computer numerical control milling machine are integrated to obtain an electrospark-computer integrated deposition system (ES-CIDS). Then, based on the ES-CIDS, a new ESD process, named electrospark-computer numerical control deposition (ES-CNCD) is developed. Furthermore, complex surface coatings are depicted using non-uniform rational B-spline mathematical model and modeled in a special software developed via MATLAB. Finally, deposition programs for a complex coating are generated using golden section interpolation method, and transferred to and executed by the ES-CIDS to accomplish the preparation of the complex surface coating.
This paper demonstrates that it is possible and feasible to prepare complex surface coatings via an automatic ESD process (namely, ES-CNCD) precisely.
This paper can make automatic ESD process get more attention from scientific researchers and engineers, and promote the research of the ES-CNCD process/equipment.
The ES-CNCD process can be used in the manufacturing of complex surface coatings, and in the remanufacturing of complex shape parts.
The ES-CIDS/ES-CNCD can promote the development of related equipment and technology, and bring opportunities and employment to ESD industry.
This work prepares complex surface coatings precisely for the first time using a new automatic ESD process (ES-CNCD), which has wide application prospects in various industries.
It has long been recognised that the durability of a paint finish is largely dependent on the condition of the metal surface beneath it. Complaints of poor durability, blistering and formation of rust are often the result of inadequate surface preparation and have no direct bearing on the quality of the paint itself. Good preparation of a metal surface is known to be essential prior to metal spraying or electroplating, and very quick failure by flaking will occur if the surface is not correctly prepared. Unfortunately, with paint, it is possible to ‘get away with it’ temporarily and hide surface defects; but before many months have passed the paint will fail and complaints are likely to be made against its quality. This comprehensive article surveys present‐day techniques in the preparation of metals for painting and includes sections on the testing of results, economics and design considerations.
THE occurrence of isolated fires in commercial, passenger carrying aircraft has focused considerable attention upon the fire risks involved in the use of combustible materials, the arrangement of functional equipment and accessories, and the effectiveness of fire‐proof finishes and coatings. In addition to other studies concerning the elimination of fire hazard through careful survey of the electrical system and other functional systems, studies have been made concerning the improvement of the ignition resistance of materials and the subsequent propagation of fire. Serious fires have developed as a result of propagation by materials which were not responsible for the original ignition of fire. An intensive effort has been made to reduce this fire hazard by the development and application of protective coatings and finishes to vulnerable and combustible materials. This work led to the obvious need for, and development of, a testing apparatus by which a realistic comparison could be made of combustible materials under conditions simulating those of an actual fire.
The aerospace industry relies heavily on protective treatments and processes to ensure that the structural integrity of an aircraft is not degraded in service as a result…
The aerospace industry relies heavily on protective treatments and processes to ensure that the structural integrity of an aircraft is not degraded in service as a result of operating under harsh corrosive conditions. Many of the chemicals and processes currently employed in metal finishing have been found to cause pollution and long‐term damage to the environment. Legislation and international agreements are now in place which ultimately will lead to a ban or major reduction in the use of many of these processes and coatings. The aircraft constructors and operators are seeking to adopt new protective schemes and treatments which will satisfy future environmental requirements.
HIGH SOLIDS COATINGS Review Articles Without question, the major motivation for high solids coatings is government regulations. An interesting article which summarises…
HIGH SOLIDS COATINGS Review Articles Without question, the major motivation for high solids coatings is government regulations. An interesting article which summarises what the coatings industry has done in order to meet air pollution regulations in the United States has been provided by Burger (Metal Finishing, July, 1982, p. 59). His list includes, in addition to high build and solventless coatings, electrodeposition, electrostatic powder coatings, Rule 66—acceptable solvent‐based coatings, and water‐borne coatings. Air pollution results not only from solvents but from the particulates released during surface preparation. Pollution due to surface preparation has been alleviated by the use of white water sandblasting, centrifugal and rotary blast cleaning blast cleaning with carbon dioxide pellets, improved ventilation air filters and safety equipment, plasma arc and laser cleaning, sonic cleaning, special chemical cleaning, and surface preparation and vacuum blasting. In addition, solvent recovery units have been utilised extensively in industrial coatings.
Repainting aircraft is a laborious and time‐consuming process, involving stripping, surface preparation and then painting. It is possible to distinguish two different…
Repainting aircraft is a laborious and time‐consuming process, involving stripping, surface preparation and then painting. It is possible to distinguish two different systems for aircraft re‐painting, owing to their prime application area, referred to as the “European System” and the “USA System”. Examines these two systems and discusses the health and environmental aspects, along with their level of corrosion protection. Examines the properties of a new binder system, referred to as the KETAC‐System. As a result of the formulation of this new binder a new primer system was developed. The development of this primer , known as Aviox CF Primer, was carried out in close co‐operation with KLM Royal Dutch Airlines, the results of which are reviewed.
Epoxy resins have probably provided more interesting chemistry than any other polymer the paint industry uses. In this category of interesting chemistry is Russian work [World Surface Coatings Abstracts (1978) Abstract No. 1558] which describes the preparation of structurally coloured epoxy resins — i.e. of epoxy resins which are inherently coloured. The work involves condensing bisphenol A and epichlorohydrin in the presence of small amounts (0.1 to 0.5 weight per cent) of a coloured co‐monomer dye. The dye, for example, can be the glycidyl ether of alpha aminoanthroquinone. Coloured products resulted which presumably would provide coatings with intrinsic colour. Of course, this colour could be modified by extrinsic dyes and pigments. The concept of producing coloured polymers is not a new one. One approach to making black polyethylene for black film is to carry out the polymerisation of the ethylene in a fluid bed of carbon particles. The carbon particles presumably serve as a nucleus around which the polymer forms and at the same time serves to impart a black colour to the polymer particle. This technology has never been commercialised but it is certainly of interest to the paint chemist for it presents a new concept in carrying out a major objective of the paint industry — namely, to impart colour to solutions of polymers.
First type isostatic lines: tangents at every point to the maximum principal deformation and stress, in algebraic values.1.0 WHEN an engineer sets out to calculate the…
First type isostatic lines: tangents at every point to the maximum principal deformation and stress, in algebraic values.
1.0 WHEN an engineer sets out to calculate the shape and dimensions of parts of machinery he becomes rapidly aware of his ignorance. Mechanical parts have such singular shapes and dimensions and are supported under such conditions that no practical method of calculation will satisfy them.
POWDER coating technology has provided a means of applying resin coatings to substrates via processing techniques which have two distinct advantages over conventional…
POWDER coating technology has provided a means of applying resin coatings to substrates via processing techniques which have two distinct advantages over conventional coating procedures. The first and probably most significant advantage from an ecological standpoint is the elimination of solvent carriers. The absence of solvents eliminates the emission of fumes and vapours thereby providing an environment that is virtually free of pollutants. Safety standards are also improved because the hazard of fire is substantially reduced.